Polymeric material, containing a latent acid

ABSTRACT

Polymeric material, containing a latent acid which can be converted to an acid by irradiation by a laser and optionally further ingredients.

This application is a Continuation of application Ser. No. 11/593,372,filed Nov. 6, 2006 which is a Divisional of application Ser. No.10/477,362, filed Nov. 12, 2003, now granted U.S. Pat. No. 7,150,958which is the National Stage of International Application No. PCT/EP02/06109, filed Jun. 4, 2002 herein incorporated entirely by reference.

The present application relates to polymeric material containing alatent acid, i.e. a compound which is not an acid but which can beconverted to an acid by the influence of irradiation.

For specific technical applications, compositions are requestedcontaining compounds which are capable of reacting with acids, however,such a reaction should be suppressed until a predetermined moment. It iscommon practice in such cases to separate the compounds and the acids bysuitable measures, e.g. by encapsulating them into coverings anddestroying these coverings when reaction is desired. This method is,however, not practicable in many cases.

The present application describes an elegant solution for that problemby using not acids but latent acids. Thus the compounds capable ofreacting with acids can be intimately mixed with the latent acidswithout reaction. No covering material is required. At the desiredmoment reaction can easily be achieved by irradiating the mixture in asuitable manner to convert the latent acid into the acid, which thenreacts with the compound.

The present application concerns polymeric material, containing a latentacid, which can be converted to an acid by irradiation and optionallyfurther ingredients.

As latent acids compounds are suitable which are not acids per se andcontain a proton, which can be split off by irradiation.

Preferred latent acids are compounds of formula

wherein the ring A can contain one or more hetero atoms and/or cancontain an anelated ring,

-   R₁ is hydrogen, alkyl, preferably C₁-C₂₀-alkyl, alkenyl, preferably    C₂-C₂₀-alkenyl, aryl, preferably phenyl or phenyl which is    substituted one to three times with C₁-C₄alkyl, or C₁-C₄alkoxy,-   R₂, R₃, R₄ and R₅ independently of each other are hydrogen or a    functional substituent, and-   R stands for C₁-C₆alkyl, -Z₁-Q₁, or -Z₂-Q₂,-   wherein Z₁ is a single bond, S, NH or O, and Q₁ is a heterocyclic    ring system having from 5to 9 ring atoms selected from C, S, O and    N, with at least 2, preferably at least 3, more preferably at least    4 carbon atoms in the ring system, preferably Q₁ stands for    morpholine, pyridine, which may be substituted one to three times    with C₁-C₄alkyl or hydroxy, mercaptobenzoxazole,    mercaptobenzthiazole,-   and wherein Z₂ stands for C₁-C₄alkylene, which can be substituted by    C₁-C₄alkyl or Q₃, wherein Q₃ stands for phenyl which can be    substituted one to three times with C₁-C₄alkyl, hydroxy,    C₅-C₈cycloalkyl and/or a heterocyclic ring system having from 5 to 9    ring atoms selected from C, S, O and N, with at least 2, preferably    at least 3, more preferably at least 4 carbon atoms in the ring    system, and Q₂ stands for phenyl which can be substituted one to    three times with C₁-C₄alkyl, hydroxy, C₅-C₈cycloalkyl and/or a    heterocyclic ring system having from 5 to 9 ring atoms selected from    C, S, O and N, with at least 2, preferably at least 3, more    preferably at least 4 carbon atoms in the ring system, with the    proviso that the hydrogen atom at the C-atom in α-position to R can    be split off by irradiation.

Preferably, Z₂ stands for —CH₂—, —CH₂—CH₂—, —CH₂—CHMe-, —CH₂—CHQ₃-, inwhich Q₃ stands for 4-hydroxy-3-i-propyl-6-methylphenyl,4-hydroxy-3-tert.-butyl-6-methylphenyl, or4-hydroxy-3-cyclohexyl-6-methylphenyl and Q₂ stands for phenyl or4-hydroxy-3-i-propyl-6-methylphenyl,4-hydroxy-3-tert.-butyl-6-methylphenyl, or4-hydroxy-3-cyclohexyl-6-methylphenyl.

Suitable rings A are e.g. phenyl, naphthyl, pyridyl and quinolinyl,phenyl and pyridyl are especially preferred.

R₁ is preferably hydrogen, or methyl.

Functional substituents R₂, R₃, R₄ and R₅ are e.g. C₁-C₂₀-alkyl,preferably C₁-C₈-alkyl, particularly preferred C₁-C₆-alkyl, especiallypreferred C₁-C₄-alkyl, C₅-C₈-cycloalkyl, C₂-C₂₀-alkenyl, preferredC₂-C₆-alkenyl, C₁-C₆-alkoxy, hydroxy, halogen, nitro, cyano, —SO₂R′,wherein R′ is hydrogen, alkyl or a metallic cation such as a alkalimetal, e.g. sodium or potassium, or earth alkali metal cation, e.g.calcium, or phenyl, which may be substituted one to three times withhydroxy and/or Z₂₁-R₇, wherein Z₂₁ stands for C₁-C₄alkylene, which canbe substituted by C₁-C₄alkyl, and R₇ stands for hydrogen, C₁-C₄alkyl orphenyl, which may be substituted one to three times with hydroxy,C₁-C₄alkyl and/or Z₂₂-R₈, wherein Z₂₂ stands for for C₁-C₄alkylene,which can be substituted by C₁-C₄alkyl, and R₈ stands for a heterocyclicring system having from 5 to 9 ring atoms selected from C, S, O and N,with at least 2, preferably at least 3, more preferably at least 4carbon atoms in the ring system, preferably R₈ stands for morpholine. Ina preferred embodiment of this invention R₂, R₃, R₄ and R₅ arepreferably independently of each other hydrogen, C₁-C₂₀-alkyl orC₂-C₂₀-alkenyl or substituted phenyl wherein hydroxy and Z₂₁-R₇ beingthe substituents. Especially preferred compounds of formula (1) arethose wherein R₂ and R₃ are independently of each other C₁-C₈-alkyl andR₄ and R₅ are each hydrogen.

Halogen means fluoro, chloro, bromo, or iodo, preferably chloro.

Heterocyclic residue or heterocyclic ring system having at least 2,preferably at least 3, more preferably at least 4 carbon atoms meanse.g. an optionally substituted monocyclic or bicycliclic heterocyclicresidue such as pyrrolidino, piperidino, morpholino, benzthiazole,1,2,4-triazole, imidazole, pyrazole, tetrazole, thiazolin-2-thione,imidazolin-2-thione, N-methyl-imidazolon-2-thione and5-(3-phenyl-1,3,4-thia-diazol-2(3H)-thione), 2-pyridine, 4-pyridine,3-pyridazine, 2-pyrimidine, 2-thiazole, 2-thioazoline,3-(1,2,4-triazole) and 5-(2-mercapto-1,3,4-thiadiazole), naphthyridine,purine and pteridine residues, benzimiazole, benzotriazole,benzoxazolin-2-thione, 2-benzoxazole, mercaptobenzoxazol,mercaptobenzthiazol and quinolinyl.

It is furthermore preferred that at least one of R₂ and R₃ is ino-position to the OH-group.

The organic residue R can be of any kind with the proviso that thehydrogen atom at the C-atom in α-position to R can be split off byirradiation. Preferably R is a heterocyclic residue which is bond via anitrogen, oxygen or sulfur atom or is a C₁-C₆-alkyl which isunsubstituted or substituted, e.g. by hydroxy, C₁-C₆-alkoxy orunsubstituted or substituted aryl, especially phenyl. Suitablesubstituents for aryl are preferably the above-mentioned substituents R₂through R₅.

Most preferably R is a radical of mercaptobenzoxazol ormercaptobenzthiazol or C₁-C₄-alkyl which is unsubstituted or substitutedby unsubstituted phenyl or phenyl carrying 1 to 4 substituents selectedfrom the group consisting of C₁-C₆-alkyl, C₁-C₄-alkoxy and hydroxy.

In preferred compounds of formula (1) the residue —CHRR₁ is situated ino- or p-, especially in p-position to the OH-group.

C₁-C₂₀-alkyl means e.g. methyl, ethyl, n-, i-propyl, n-, sec.-, iso-,tert.-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl,n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl,n-hexadecyl, n-heptadecyl, n-octadecyl, n-nonadecyl, n-eicosyl,preferably C₁-C₈-alkyl such as methyl, ethyl, n-, i-propyl, n-, sec.-,iso-, tert.-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, particularlypreferred C₁-C₆-alkyl such as methyl, ethyl, n-, i-propyl, n-, sec.-,iso-, tert.-butyl, n-pentyl, n-hexyl, especially preferred C₁-C₄-alkylsuch as methyl, ethyl, n-, i-propyl, n-, sec.-, iso-, tert.-butyl.

C₅-C₈-cycloalkyl stands for cyclopentyl, cyclohexyl, cycloheptyl, orcyclooctyl, preferably cyclohexyl.

C₂-C₂₀-alkenyl stands for e.g. ethenyl, n-, i-propenyl, n-, sec.-, iso-,tert.-butenyl, n-pentenyl, n-hexenyl, n-heptenyl, n-octenyl, n-nonenyl,n-decenyl, n-undecenyl, n-dodecenyl, n-tridecenyl, n-tetradecenyl,n-pentadecenyl, n-hexadecenyl, n-heptadecenyl, n-octadecenyl,n-nonadecenyl, n-eicosenyl, preferably C₂-C₆-alkyl such as ethenyl, n-,i-propenyl, n-, sec.-, iso-, tert.-butenyl, n-pentenyl, n-hexenyl.

C₁-C₆-alkoxy stands for e.g. methoxy, ethoxy, n-, i-propoxy, n-, sec.-,iso-, tert.-butoxy, n-pentoxy, n-hexoxy.

Preferred polymeric material according to the present invention containsa latent acid of formula (1) wherein the ring A is phenyl or pyridyl,

-   R₁ is hydrogen,-   R₂ and R₃ are independently of each other C₁-C₄-alkyl,-   R₄ and R₅ are each hydrogen and-   R is a heterocyclic residue, which is bond to the CHR₁-group via a    nitrogen, oxygen or sulfur atom or is a C₁-C₆-alkyl, which is    unsubstituted or substituted.

Especially preferred compounds of formula (1) are the followingcompounds:

The compounds of formula (1) are known or can be made in a manner knownper se, e.g. compound (2) according to GB 2,120,243 and compounds (5)and (6) as described in EP-A-330 613.

The compounds of the above formulae (7) and (8) are new. These compoundsalso form part of the subject matter of the present invention. They canbe obtained in a conventional manner by reaction ofmercaptobenzothiazole with a 2,5-dialkylphenol and paraformaldehyde.

Polymeric material useable for the present invention is preferablysynthetic organic polymeric material, especially material commonly usedfor electronic applications.

In particular the following polymers are preferred:

-   1. Polymers of monoolefins and diolefins, for example polypropylene,    polyisobutylene, polybut-1-ene, poly-4-methylpent-1-ene,    polyvinylcyclohexane, polyisoprene or polybutadiene, as well as    polymers of cycloolefins, for instance of cyclopentene or    norbornene, polyethylene (which optionally can be crosslinked), for    example high density polyethylene (HDPE), high density, and high    molecular weight polyethylene (HDPE-HMW), high density and ultrahigh    molecular weight polyethylene (HDPE-UHMW), medium density    polyethylene (MDPE), low density polyethylene (LDPE), linear low    density polyethylene (LLDPE), (VLDPE) and (ULDPE).

Polyolefins, i.e. the polymers of monoolefins exemplified in thepreceding paragraph, preferably polyethylene and polypropylene, can beprepared by different, and especially by the following, methods:

-   -   a) radical polymerisation (normally under high pressure and at        elevated temperature).    -   b) catalytic polymerisation using a catalyst that normally        contains one or more than one metal of groups IVb, Vb, VIb or        VIII of the Periodic Table. These metals usually have one or        more than one ligand, typically oxides, halides, alcoholates,        esters, ethers, amines, alkyls, alkenyls and/or aryls that may        be either π- or σ-coordinated. These metal complexes may be in        the free form or fixed on substrates, typically on activated        magnesium chloride, titanium(III) chloride, alumina or silicon        oxide. These catalysts may be soluble or insoluble in the        polymerisation medium. The catalysts can be used by themselves        in the polymerisation or further activators may be used,        typically metal alkyls, metal hydrides, metal alkyl halides,        metal alkyl oxides or metal alkyloxanes, said metals being        elements of groups Ia, IIa and/or IIIa of the Periodic Table.        The activators may be modified conveniently with further ester,        ether, amine or silyl ether groups. These catalyst systems are        usually termed Phillips, Standard Oil Indiana, Ziegler (-Natta),        TNZ (DuPont), metallocene or single site catalysts (SSC).

-   2. Mixtures of the polymers mentioned under 1), for example mixtures    of polypropylene with polyisobutylene, polypropylene with    polyethylene (for example PP/HDPE, PP/LDPE) and mixtures of    different types of polyethylene (for example LDPE/HDPE).

-   3. Copolymers of monoolefins and diolefins with each other or with    other vinyl monomers, for example ethylene/propylene copolymers,    linear low density polyethylene (LLDPE) and mixtures thereof with    low density polyethylene (LDPE), propylene/but-1-ene copolymers,    propylene/isobutylene copolymers, ethylene/but-1-ene copolymers,    ethylene/hexene copolymers, ethylene/methylpentene copolymers,    ethylene/heptene copolymers, ethylene/octene copolymers,    ethylene/vinylcyclohexane copolymers, ethylene/cycloolefin    copolymers (e.g. ethylene/norbornene like COC), ethylene/1-olefins    copolymers, where the 1-olefin is generated in-situ;    propylene/butadiene copolymers, isobutylene/isoprene copolymers,    ethylene/vinylcyclohexene copolymers, ethylene/alkyl acrylate    copolymers, ethylene/alkyl methacrylate copolymers, ethylene/vinyl    acetate copolymers or ethylene/acrylic acid copolymers and their    salts (ionomers) as well as terpolymers of ethylene with propylene    and a diene such as hexadiene, dicyclopentadiene or    ethylidene-norbornene; and mixtures of such copolymers with one    another and with polymers mentioned in 1) above, for example    polypropylene/ethylene-propylene copolymers, LDPE/ethylene-vinyl    acetate copolymers (EVA), LDPE/ethylene-acrylic acid copolymers    (EAA), LLDPE/EVA, LLDPE/EAA and alternating or random    polyalkylene/carbon monoxide copolymers and mixtures thereof with    other polymers, for example polyamides.

-   4. Hydrocarbon resins (for example C₅-C₉) including hydrogenated    modifications thereof (e.g. tackifiers) and mixtures of    polyalkylenes and starch.

Homopolymers and copolymers from 1.)-4.) may have any stereostructureincluding syndiotactic, isotactic, hemi-isotactic or atactic; whereatactic polymers are preferred. Stereoblock polymers are also included.

-   5. Polystyrene, poly(p-methylstyrene), poly(α-methylstyrene).-   6. Aromatic homopolymers and copolymers derived from vinyl aromatic    monomers including styrene, α-methylstyrene, all isomers of vinyl    toluene, especially p-vinyltoluene, all isomers of ethyl styrene,    propyl styrene, vinyl biphenyl, vinyl naphthalene, and vinyl    anthracene, and mixtures thereof. Homopolymers and copolymers may    have any stereostructure including syndiotactic, isotactic,    hemi-isotactic or atactic; where atactic polymers are preferred.    Stereoblock polymers are also included.-   6a. Copolymers including aforementioned vinyl aromatic monomers and    comonomers selected from ethylene, propylene, dienes, nitriles,    acids, maleic anhydrides, maleimides, vinyl acetate and vinyl    chloride or acrylic derivatives and mixtures thereof, for example    styrene/butadiene, styrene/acrylonitrile, styrene/ethylene    (interpolymers), styrene/alkyl methacrylate, styrene/butadiene/alkyl    acrylate, styrene/butadiene/alkyl methacrylate, styrene/maleic    anhydride, styrene/acrylonitrile/methyl acrylate; mixtures of high    impact strength of styrene copolymers and another polymer, for    example a polyacrylate, a diene polymer or an    ethylene/propylene/diene terpolymer; and block copolymers of styrene    such as styrene/butadiene/styrene, styrene/isoprene/styrene,    styrene/ethylene/butylene/styrene or    styrene/ethylene/propylene/styrene.-   6b. Hydrogenated aromatic polymers derived from hydrogenation of    polymers mentioned under 6.), especially including    polycyclohexylethylene (PCHE) prepared by hydrogenating atactic    polystyrene, often referred to as polyvinylcyclohexane (PVCH).-   6c. Hydrogenated aromatic polymers derived from hydrogenation of    polymers mentioned under 6a.).

Homopolymers and copolymers may have any stereostructure includingsyndiotactic, isotactic, hemi-isotactic or atactic; where atacticpolymers are preferred. Stereoblock polymers are also included.

-   7. Graft copolymers of vinyl aromatic monomers such as styrene or    α-methylstyrene, for example styrene on polybutadiene, styrene on    polybutadiene-styrene or polybutadiene-acrylonitrile copolymers;    styrene and acrylonitrile (or methacrylonitrile) on polybutadiene;    styrene, acrylonitrile and methyl methacrylate on polybutadiene;    styrene and maleic anhydride on polybutadiene; styrene,    acrylonitrile and maleic anhydride or maleimide on polybutadiene;    styrene and maleimide on polybutadiene; styrene and alkyl acrylates    or methacrylates on polybutadiene; styrene and acrylonitrile on    ethylene/propylene/diene terpolymers; styrene and acrylonitrile on    polyalkyl acrylates or polyalkyl methacrylates, styrene and    acrylonitrile on acrylate/butadiene copolymers, as well as mixtures    thereof with the copolymers listed under 6), for example the    copolymer mixtures known as ABS, MBS, ASA or AES polymers.-   8. Halogen-containing polymers such as polychloroprene, chlorinated    rubbers, chlorinated and brominated copolymer of    isobutylene-isoprene (halobutyl rubber), chlorinated or    sulfo-chlorinated polyethylene, copolymers of ethylene and    chlorinated ethylene, epichlorohydrin, homo- and copolymers,    especially polymers of halogen-containing vinyl compounds, for    example polyvinyl chloride, polyvinylidene chloride, polyvinyl    fluoride, polyvinylidene fluoride, as well as copolymers thereof    such as vinyl chloride/vinylidene chloride, vinyl chloride/vinyl    acetate or vinylidene chloride/vinyl acetate copolymers.-   9. Polymers derived from α,β-unsaturated acids and derivatives    thereof such as polyacrylates and polymethacrylates; polymethyl    methacrylates, polyacrylamides and polyacrylonitriles,    impact-modified with butyl acrylate.-   10. Copolymers of the monomers mentioned under 9) with each other or    with other unsaturated monomers, for example acrylonitrile/butadiene    copolymers, acrylonitrile/alkyl acrylate copolymers,    acrylonitrile/alkoxyalkyl acrylate or acrylonitrile/vinyl halide    copolymers or acrylonitrile/alkyl methacrylate/butadiene    terpolymers.-   11. Polymers derived from unsaturated alcohols and amines or the    acyl derivatives or acetals thereof, for example polyvinyl alcohol,    polyvinyl acetate, polyvinyl stearate, polyvinyl benzoate, polyvinyl    maleate, polyvinyl butyral, polyallyl phthalate or polyallyl    melamine; as well as their copolymers with olefins mentioned in 1)    above.-   12. Homopolymers and copolymers of cyclic ethers such as    polyalkylene glycols, polyethylene oxide, polypropylene oxide or    copolymers thereof with bisglycidyl ethers.-   13. Polyacetals such as polyoxymethylene and those    polyoxymethylenes, which contain ethylene oxide as a comonomer;    polyacetals modified with thermoplastic polyurethanes, acrylates or    MBS.-   14. Polyphenylene oxides and sulfides, and mixtures of polyphenylene    oxides with styrene polymers or polyamides.-   15. Polyurethanes derived from hydroxyl-terminated polyethers,    polyesters or polybutadienes on the one hand and aliphatic or    aromatic polyisocyanates on the other, as well as pre-cursors    thereof.-   16. Polyamides and copolyamides derived from diamines and    dicarboxylic acids and/or from aminocarboxylic acids or the    corresponding lactams, for example polyamide 4, polyamide 6,    polyamide 6/6, 6/10, 6/9, 6/12, 4/6, 12/12, polyamide 11, polyamide    12, aromatic polyamides starting from m-xylene diamine and adipic    acid; polyamides prepared from hexamethylenediamine and isophthalic    or/and terephthalic acid and with or without an elastomer as    modifier, for example poly-2,4,4-trimethylhexamethylene    terephthalamide or poly-m-phenylene isophthalamide; and also block    copolymers of the aforementioned polyamides with polyolefins, olefin    copolymers, ionomers or chemically bonded or grafted elastomers; or    with polyethers, e.g. with polyethylene glycol, polypropylene glycol    or polytetramethylene glycol; as well as polyamides or copolyamides    modified with EPDM or ABS; and polyamides condensed during    processing (RIM polyamide systems).-   17. Polyureas, polyimides, polyamide-imides, polyetherimids,    polyesterimids, polyhydantoins and polybenzimidazoles.-   18. Polyesters derived from dicarboxylic acids and diols and/or from    hydroxycarboxylic acids or the corresponding lactones, for example    polyethylene terephthalate, polybutylene terephthalate,    poly-1,4-dimethylolcyclohexane terephthalate, polyalkylene    naphthalate (PAN) and polyhydroxybenzoates, as well as block    copolyether esters derived from hydroxyl-terminated polyethers; and    also polyesters modified with polycarbonates or MBS.-   19. Polycarbonates and polyester carbonates.-   20. Polyketones.-   21. Polysulfones, polyether sulfones and polyether ketones.-   22. Crosslinked polymers derived from aldehydes on the one hand and    phenols, ureas and melamines on the other hand, such as    phenol/formaldehyde resins, urea/formaldehyde resins and    melamine/formaldehyde resins.-   23. Drying and non-drying alkyd resins.-   24. Unsaturated polyester resins derived from copolyesters of    saturated and unsaturated dicarboxylic acids with polyhydric    alcohols and vinyl compounds as crosslinking agents, and also    halogen-containing modifications thereof of low flammability.

25. Crosslinkable acrylic resins derived from substituted acrylates, forexample epoxy acrylates, urethane acrylates or polyester acrylates.

-   26. Alkyd resins, polyester resins and acrylate resins crosslinked    with melamine resins, urea resins, isocyanates, isocyanurates,    polyisocyanates or epoxy resins.-   27. Crosslinked epoxy resins derived from aliphatic, cycloaliphatic,    heterocyclic or aromatic glycidyl compounds, e.g. products of    diglycidyl ethers of bisphenol A and bisphenol F, which are    crosslinked with customary hardeners such as anhydrides or amines,    with or without accelerators.-   28. Natural polymers such as cellulose, rubber, gelatin and    chemically modified homologous derivatives thereof, for example    cellulose acetates, cellulose propionates and cellulose butyrates,    or the cellulose ethers such as methyl cellulose; as well as rosins    and their derivatives.-   29. Blends of the aforementioned polymers (polyblends), for example    PP/EPDM, Polyamide/EPDM or ABS, PVC/EVA, PVC/ABS, PVC/MBS, PC/ABS,    PBTP/ABS, PC/ASA, PC/PBT, PVC/CPE, PVC/acrylates, POM/thermoplastic    PUR, PC/thermoplastic PUR, POM/acrylate, POM/MBS, PPO/HIPS, PPO/PA    6.6 and copolymers, PA/HDPE, PA/PP, PA/PPO, PBT/PC/ABS or    PBT/PET/PC.

Especially preferred is organic polymeric material made of SAN(copolymer made of styrene and acrylonitrile), PP (polypropylene), PE(polyethylene), PVC (polyvinylchloride), PET(polyethyleneterephthalate), PET-G (glycole-modified PET), PMMA(polymethylmethacrylate) and related polyacrylics, PS (polystyrene), ASA(copolymer made of acrylonitrile, styrene, acrylate), PA (polyamide),ABS (copolymer made of acrylonitrile, styrene, butadiene), LLDPE (linearLDPE), LDPE (low density polyethylene), HDPE (high density polyethylene)and polycarbonate, most preferably polycarbonate. The polymeric materialcan also be a mixture of two or more different polymers.

The polymeric material usually contains preferably 0.001 to 10% byweight, most preferably 0.01 to 5% by weight of the latent acid (1). Thepolymeric material may also contain mixtures of two or more of thelatent acids.

The polymeric material and the latent acid usually form a homogenousmixture. For specific applications, however, compositions can be made inwhich the latent acid is enriched in a specific part of the polymericmaterial, e.g. in the surface areas.

The methods for incorporating the latent acid into the polymericmaterial are in principle known. It is e.g. possible, to dissolve thecomponents in a solvent and then to remove the solvent by evaporation.Another possibility is to melt polymeric material together with thelatent acid to get a homogeneous mixture or to thoroughly knead amixture of polymeric material and latent acid, or to polymerize thecorresponding monomers in the presence of the latent acid.

In another embodiment of this invention, the latent acid (1) is graftedon the polymer material by means known in the art. E.g. the latent acid(1) is converted into a monomer, i.e. by incorporating a functionalpolymerizable group, or a monomer is used which is functionalized with alatent acid group. This allows a graft polymerization on the existingpolymeric material or a copolymerization during the manufacturing thepolymeric material.

The polymeric material usually may contain further ingredients, e.g.stabilizers, antioxidants, softeners etc. as are commonly used forpolymeric material.

To convert the latent acid into the corresponding acid, the polymericmaterial is irradiated. Irradiation in this application especially meansirradiation with UV-light and especially with UV-lasers. As a rule, thelasers used are commercially available. The wavelength of the UV-lightpreferably is chosen in the range of 285 to 400 nm, particularlypreferred in the range of 285 to 370 nm. The duration of irradiationdepends on the components and on the type of UV-source and be easily bedetermined by simple experiments.

The inventive polymeric material containing a latent acid can be used ina system for laser decoration if the polymeric material additionallycontains a colourless colour former which gives a visible colour afterreaction with an acid.

The following non-limitative examples illustrate the invention in moredetail. Parts and percentages are by weight, unless otherwise stated.

EXAMPLES Example 1

To a reaction flask are charged 16.7 g of mercaptobenzothiazole, 16.4 g2-t-butyl-5-methylphenol, 3.0 g paraformaldehyde and 1 ml dibutylamine.The mixture is heated to 120° C. and held at this temperature for 6hours. After cooling to room temperature 75 ml ethanol are added. Thenthe mixture is heated to reflux for 2 hours and then cooled to 20° C.and filtered. By trituration of the product with hot methanol a productwith melting point 177.9-183.9° C. is obtained. The product is of thefollowing formula:

Yield 22.5 g (65.6% theory).

Example 2

Repeating Example 1, but replacing 2-t-butyl-5-methylphenol by 15.0 gthymol gives a compound of formula

Melting point 119.3-123.0. Yield 9.6 g (29.2% theory).

Example 3

100 parts of polycarbonate, and 1 part of the latent acid according toexample 1and 1 part of the colour former of the formula

are dissolved in tetrahydrofurane. The solvent is allowed to evaporateovernight.

A colourless homogeneous polymeric material is obtained. Irradiationwith a UV-laser at 355 nm produces blue marks at the irradiated areas.

Examples 4 to 8

In a similar manner to example 3 the following latent acids areincorporated in polycarbonate:

Example Latent Acid Parts latent acid Parts Colour Former 4 Compound (2)1 1 5 Compound (8) 1 1 6 Compound (11) 1 1 7 Compound (12) 1 1 8Compound (13) 1 1

In each case irradiation with a laser at 355 nm produced a clear bluemark.

1. Polymeric material, containing a latent acid, which can be convertedto an acid by irradiation by a laser, and optionally furtheringredients, wherein the latent acid is of formula

wherein the ring A can contain one or more hetero atoms and/or cancontain an anelated ring, R₁ is hydrogen, alkyl, alkenyl, aryl, R₂, R₃,R₄ and R₅ independently of each other are hydrogen or a functionalsubstituent, and R stands for -Z₁-Q₁, or -Z₂-Q₂, wherein Z₁ is a singlebond, S, NH or O, and Q₁ is a heterocyclic ring system having from 5 to9 ring atoms selected from C, S, O and N, with at least 2 carbon atomsin the ring system, which may be substituted one to three times withC₁-C₄alkyl or hydroxy, mercaptobenzoxazole, mercaptobenzthiazole, andwherein Z₂ stands for C₁-C₄alkylene, which can be substituted byC₁-C₄alkyl or Q₃, wherein Q₃ stands for phenyl which can be substitutedone to three times with C₁-C₄alkyl, hydroxy, C₅-C₈cycloalkyl and/or aheterocyclic ring system having from 5 to 9 ring atoms selected from C,S, O and N, with at least 2 carbon atoms in the ring system, and Q₂stands for a heterocyclic ring system having from 5 to 9 ring atomsselected from C, S, O and N, with at least 2 carbon atoms in the ringsystem, with the proviso that the hydrogen atom at the C-atom inα-position to R can be split off by irradiation and the heterocyclicring systems of Q₁ or Q₂ are the optionally substituted heterocyclicresidues pyrrolidino, piperidino, morpholino, benzthiazole,1,2,4-triazole, imidazole, pyrazole, tetrazole, thiazolin-2-thione,imidazolin-2-thione, N-methyl-imidazolon-2-thione and5-(3-phenyl-1,3,4-thiadiazol-2(3H)-thione), 2-pyridine, 4-pyridine,3-pyridazine, 2-pyrimidine, 2-thiazole, 2-thioazoline,3-(1,2,4-triazole) and 5-(2-mercapto-1,3,4-thiadiazole), naphthyridine,purine and pteridine residues, benzimidazole, benzotriazole,benzoxazolin-2-thione, 2-benzoxazole, mercaptobenzoxazol,mercaptobenzthiazol or quinolinyl.
 2. The polymeric material accordingto claim 1, wherein the polymeric material contains 0.001 to 10% byweight by weight of the latent acid.
 3. The polymeric material accordingto claim 1, wherein the polymeric material further contains a colourlesscolour former which gives a visible colour after reaction with an acid.4. The polymeric material according to claim 1, wherein R₁ is hydrogenor methyl.
 5. The polymeric material according to claim 1, wherein R isa heterocyclic residue, which is bound to the CHR₁ group via a nitrogen,oxygen or sulfur atom, which is unsubstituted or substituted.
 6. Thepolymeric material according to claim 1, wherein R is a radical ofmercaptobenzoxazol or mercaptobenzthiazole which is unsubstituted orsubstituted by unsubstituted phenyl or phenyl carrying 1 to 4substitutent selected from the group consisting of C₁-C₆ alkyl, C₁-C₄alkyoxy and hydroxyl.
 7. The polymeric material according to claim 1,wherein the polymeric material contains as further ingredient astabilizer, an antioxidant or a softener.
 8. The polymeric materialaccording to claim 1, wherein the latent acid of formula (1) is at leastone compound selected from the group consisting of compounds representedby formulae (3), (4), (5), (6), (7), (8), (9), (10), (11) and (12)